Why does my object not show up?
This is the overview. I am breaking up the parts into individual answers that we can link to from other questions. This is a community wiki, so feel free to add ones that need to be addressed completely in another answer. If you decide to add another answer, please follow the pattern that I used with the first individual answer. This will make it easy to send people to this question or a particular answer while knowing that their question will be answered completely.
Invisible to the render

Camera icon is disabled in the outliner

Render layer not showing in the compositor

Render layer does not include scene layer or the objects are in a layer that is not renderable.

Scene layer not selected

Cycles camera visibility disabled in object settings

Cycles material disables visibility to the camera

Objects are not within the range set by the camera clipping

Using the wrong scene

Strips present in the VSE, and the sequencer box is enabled in the post process section

Cycles: Exposure setting in the film section set to 0

Depth of field not set properly making the whole scene blurry

Object blocking the camera view

An object has been set as the active camera.

There are no lights on the scene or they are on a different layer.

Objects have no faces

The Solidify modifier takes over the object and is disabled in Viewport

Duplication type set to 'Group' and no group is selected.

Duplication issues (under the Object tab in the properties panel), e.g., duplication type is not 'None', and object has no childen, or set to 'Group' and no group is selected.

Render layer In Node editor is muted (disabled)

Cycles materials don't have a shader node

Camera is not pointed at object

Save your data to .blend before rendering with Cycles/Eevee (Blender 2.8)

Object has a particle system with emitter visibility disabled and/or no particles

Cycles Filter is active


Invisible in the viewport

Object is hidden
3D view clipping distance set too high/low
Scene layer not selected
Using the wrong scene
Object is moved far away
Using local view
View Border is active (Alt+B)
Cycles Filter is active (same as #24 for the &quot;render&quot; list above)


Note: I will be adding reference images, details, and links as time allows. Hopefully this will be helpful to someone. If you think of something that I missed, feel free to suggest an edit.

Questions about problems that have not yet been addressed
Why Does My Object Not Show in Rendered Shading Mode?
Why do some objects not show up in the camera view?